EXHIBIT 5.1

              [Letterhead of Cleary, Gottlieb, Steen and Hamilton]

                                  July 7, 1999


Morgan Stanley & Co. Incorporated
1585 Broadway
New York, New York  10036

MSDW Structured Asset Corp.
1585 Broadway
New York, New York  10036

Ladies and Gentlemen:

     We have acted as special counsel to MSDW Structured Asset Corp., a Delaware
corporation (the "Depositor") in connection with the Depositor's preparation and
filing with the Securities and Exchange Commission (the "Commission") a
registration statement on Form S-3 (File No. 333-64879 (the "Registration
Statement")) and the related prospectus (the "Prospectus"), first filed on
September 30, 1998 and amended by filings on February 24, 1999, April 28, 1999,
and July 7, 1999, with respect to the offering of Structured Asset Trust Unit
Repackagings (the "Units"), which the Depositor plans to offer in series. Each
Series of Units will be issued under a separate Trust Agreement (a "Trust
Agreement"), in all material respects relevant hereto incorporating the Standard
Terms of Trust Agreements dated as of July 7, 1999 (the "Standard Terms")
between the Depositor and Chase Bank of Texas, National Association ("Chase Bank
of Texas"), as trustee, in the form included as an exhibit to the Registration
Statement, between the Depositor and Chase Bank of Texas or another trustee to
be identified in the prospectus supplement for such series of Units (the
"Trustee" for such series).

     In arriving at the opinions expressed below, we have reviewed the following
documents:

     (a) the Registration Statement and the related Prospectus and the documents
incorporated by reference therein;

     (b) the Standard Terms; and

     (c) forms of the Units set forth in the Standard Terms.

     In addition, we have reviewed the originals or copies certified or
otherwise identified to our satisfaction of all such corporate records of the
Depositor and such other instruments and other certificates of public officials,
officers and representatives of the Depositor and such other persons, and we
have made such investigations of law, as we have deemed appropriate as a basis
for the opinions expressed below.

     In rendering the opinions expressed below, we have assumed the authenticity
of all documents submitted to us as originals and the conformity to the
originals of all documents submitted to us as copies. In addition, we have
assumed and have not verified the accuracy as to factual matters of each
document we have reviewed (including, without limitation, the accuracy of the
representations and warranties of the Depositor in the Standard Terms).

     Based on the foregoing, and subject to the further assumptions and
qualifications set forth below, it is our opinion that:

     1. When, in respect of a series of Units, a Trust Agreement has been duly
authorized by all necessary action of, and duly executed and delivered by the
Depositor and the Trustee for such series, such Trust Agreement will be a valid,
binding and enforceable obligation of the Depositor; and

     2. When a Trust Agreement for a series of Units has been duly authorized by
all necessary action of, and duly executed and delivered by, the Depositor and
the Trustee for such series, and when the Units of such series have been duly
executed and countersigned in accordance with the terms of the Trust Agreement
and issued and sold as contemplated in the Registration Statement and the
prospectus with respect to such series delivered pursuant to Section 5 of the
Act, such Units will be legally and validly issued, the holders of such Units
will be entitled to the benefits of such Trust Agreement, and such Units will be
fully paid and nonassessable.

     Insofar as the foregoing opinions relate to the validity, binding effect or
enforceability of any agreement or obligation (a) we have assumed that each
other party to such agreement or obligation other than the Depositor has
satisfied those legal requirements that are applicable to it to the extent
necessary to make such agreement or obligation enforceable against it, and (b)
such opinions are subject to applicable bankruptcy, insolvency and similar laws
affecting creditors' rights generally and to general principles of equity.

     The foregoing opinions are limited to the federal law of the United States
of America, and the law of the State of New York.

     We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement and the reference to this firm in the Registration
Statement and the related Prospectus under the caption "Legal Matters." By
giving such consent, we do not admit that we are "experts" within the meaning of
the Act, or the rules and regulations of the Commission issued thereunder with
respect to any part of the Registration Statement, including this exhibit.

                                  Very truly yours,

                                  CLEARY, GOTTLIEB, STEEN & HAMILTON



                                  By /s/ Mitchell S. Dupler
                                     -----------------------
                                     Mitchell S. Dupler, a Partner