Versatile diastereoselectivity in formal [3,3]-sigmatropic shifts of substituted 1-alkenyl-3-alkylidenecyclobutanols and their silyl ethers

Journal of the American Chemical Society

Volumn 127, Issue 32, 2005, Pages 11206-11207

  Jung, Michael E ^a   Nishimura, Nobuko ^a   Novack, Aaron R ^a  

^a UNIVERSITY OF CALIFORNIA   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

2 CYCLOHEXENONE; ACID; ALCOHOL; ALKENE; BASE; BUTANOL; CARBOXYLIC ACID DERIVATIVE; CYCLOBUTANOL DERIVATIVE; CYCLOHEXENE; ESTER; LITHIUM DERIVATIVE; METAL DERIVATIVE; SILANE DERIVATIVE; TOLUENE; UNCLASSIFIED DRUG;

ARTICLE; CATALYSIS; CYCLIZATION; CYCLOADDITION; DIASTEREOISOMER; DISSOCIATION; ELECTRON; HEATING; HYDROLYSIS; ISOMER; LOW TEMPERATURE; LYSIS; MICHAEL ADDITION; REACTION ANALYSIS; ROTATION; STEREOCHEMISTRY; STOICHIOMETRY; THERMOLYSIS;

EID: 23844492744     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja051663p     Document Type: Article

References (15)

1. (a) Jung, M. E.; Nishimura, N. J. Am. Chem. Soc. 1999, 121, 3529.
2. (b) Jung, M. E.; Nishimura, N. Org. Lett. 2001, 3, 2113.
3. (a) Dolbier, W. R., Jr.; Mancini, G. J. Tetrahedron Lett. 1975, 2141.
4. (b) Dolbier, W. R., Jr.; Piedrahita, C. A.; Al-Sader, B. H. Tetrahedron Lett. 1979, 2957.
5. (c) Spitzner, D. Angew. Chem. 1982, 94, 639.
6. (d) Kozhushkov, S. I.; Kuznetsova, T. S.; Zefirov, N. S. Dokl. Akad. Nauk SSSR 1988, 299, 1395-1399.
7. (e) Spitzner, D.; Klein, I. Liebigs Ann. Chem. 1990, 63.
8. 1a
9. For a review of flash vacuum pyrolysis, see: Trahanovsky, W. S.; Lee, S. K. Synthesis 1996, 1085-1086 and references therein.
10. The use of various solvents for this process showed that moderately polar solvents, such as chlorobenzene, 1,2-dichlorobenzene, THF, etc., accelerated the rearrangement by a factor of about 4-5, whereas very polar solvents, such as DMF and DMSO, gave the two triene products (approximately 1:1 mixture) via solvolysis of the tertiary silyl ether.
11. This produced the same approximately 1:1 mixture of triene esters as did heating in DMSO or DMF.
12. Although hexa-1,5-dien-3-olates are well-known to rearrange to enones (e.g., anionic oxy-Cope), there are no examples of this process with an 3-methylene-1-alkenylcyclobutan-1-ol system such as these.
13. (a) Harris, F. L.; Weiler, L. Tetrahedron Lett. 1985, 26, 1939.
14. (b) Harris, F. L.; Weiler, L. Tetrahedron Lett. 1984, 25, 1333. Deprotonation of stereospecifically dcuterated 3-methylcrotonate was carried out with LDA in the presence of HMPA, so that it is not clear whether an association of the lithium base with the carbonyl was the determining factor in the stereochemical course of the reaction (syn deprotonation).
15. The yield of the [2 + 2] product 20 is somewhat low because the aryl group in monoaryl substituted systems accelerates the rearrangement to give the exo products (e.g., 21x) during the heating required to prepare the cyclobutane. This is not the case for monoalkyl substituted systems (e.g., 3), where the yield is generally 80% or so.