<PAGE>
EXHIBIT 5.1
CONSENT OF INDEPENDENT ACCOUNTANTS
We consent to the use in this Amendment No. 1 to Registration Statement No.
333-42734 on Form S-6 of our report dated October 20, 2000 relating to the
Statements of Condition of the California Insured Portfolio and New York Insured
Portfolio of Municipal Investment Trust Fund, Multistate Series--417, Defined
Asset Funds and to the reference to us under the heading "How the Fund
Works--Auditors" in the Prospectus which is a part of this Registration
Statement.
DELOITTE & TOUCHE LLP
New York, NY
October 20, 2000
