[77197-59-2]  · C7H16O4  · 1,1,1,3-Tetramethoxypropane  · (MW 164.23)

(furnishes methyl a-substituted acrylates from allylic alcohols via Claisen orthoester rearrangement and b-elimination1-5)

Physical Data: bp 89-90 °C/20 mmHg.1

Solubility: CCl4, organic solvents.

Handling, Storage, and Precautions: keep away from moisture; use in a fume hood.

General Discussion.

1,1,1,3-Tetramethoxypropane (1) is prepared1 from b-methoxypropionitrile6 by the Pinner reaction.7 It has been used as a synthon for the preparation of methyl a-substituted acrylates via Claisen orthoester rearrangement8 with allylic alcohols followed by b-elimination of methanol with base. Claisen orthoester rearrangement of allylic alcohols (2)-(4) with excess (1) and a catalytic amount of 2,4,6-trimethylbenzoic acid gave the esters (5)-(7).1 Treatment of these esters with one equivalent of Potassium t-Butoxide in THF (0 °C, 10 min) gave the a-substituted acrylates (8)-(10).1

The conversion of (11) to (12) and then (13) using this methodology has been reported.5

Another report describes the Claisen rearrangement of (14)1 and (15).2,3 These rearrangements, requiring a larger amount of acid catalyst and longer reaction times, provide the a-substituted acrylates (16) and (17) directly.

1. Raucher, S.; Macdonald, J. E.; Lawrence, R. F. TL 1980, 21, 4335.
2. Raucher, S.; Macdonald, J. E.; Lawrence, R. F. JACS 1981, 103, 2419.
3. Raucher, S.; Lawrence, R. F. T 1983, 39, 3731.
4. Sworin, M.; Lin, K. C. JACS 1989, 111, 1815.
5. Sworin, M.; Lin, K. C. JOC 1987, 52, 5640.
6. MacGregor, J. H.; Pugh, C. JCS 1945, 535.
7. DeWolfe, R. H. S 1974, 153.
8. (a) Rhoads, S. J.; Raulins, N. R. OR 1975, 22, 1. (b) Johnson, W. S.; Wertheman, L.; Bartlett, W. R.; Brocksom, T. J.; Lee, T.-T.; Faulkner, D. J.; Petersen, M. R. JACS 1970, 92, 741.

Stanley Raucher

University of Washington, Seattle, WA, USA

Copyright 1995-2000 by John Wiley & Sons, Ltd. All rights reserved.