Header

UZH-Logo

Maintenance Infos

Reaction of thiocarbonyl S-methylides with acetylenic dipolarophiles and an unexpected rearrangement of the cycloadducts


Gendek, Tomasz; Mloston, Grzegorz; Linden, Anthony; Heimgartner, Heinz (2002). Reaction of thiocarbonyl S-methylides with acetylenic dipolarophiles and an unexpected rearrangement of the cycloadducts. Helvetica Chimica Acta, 85:451-463.

Abstract

The 1,3-dipolar cycloaddition of 2,2,4,4-tetramethyl-3-thioxocyclobutanone S-methylide (2a), generated in situ by thermal extrusion of N2 from the corresponding 2,5-dihydro-1,3,4-thiadiazole 1a, with electron-deficient acetylenic compounds yields spirocyclic 2,5-dihydrothiophene derivatives of type 4 (Scheme 2). Mixtures of diastereoisomers are obtained in the case of propiolates. The strained cyclooctyne also undergoes smooth cycloadditions with thioketone S-methylides (Scheme 3). Under acidic conditions, the spirocyclic products of type 4 and 6a isomerize, via opening of the cyclobutanone ring and aromatization of the five-membered ring, to thiophene derivatives of type 7 (Scheme 4).

Abstract

The 1,3-dipolar cycloaddition of 2,2,4,4-tetramethyl-3-thioxocyclobutanone S-methylide (2a), generated in situ by thermal extrusion of N2 from the corresponding 2,5-dihydro-1,3,4-thiadiazole 1a, with electron-deficient acetylenic compounds yields spirocyclic 2,5-dihydrothiophene derivatives of type 4 (Scheme 2). Mixtures of diastereoisomers are obtained in the case of propiolates. The strained cyclooctyne also undergoes smooth cycloadditions with thioketone S-methylides (Scheme 3). Under acidic conditions, the spirocyclic products of type 4 and 6a isomerize, via opening of the cyclobutanone ring and aromatization of the five-membered ring, to thiophene derivatives of type 7 (Scheme 4).

Statistics

Citations

3 citations in Web of Science®
10 citations in Scopus®
Google Scholar™

Altmetrics

Downloads

1 download since deposited on 03 Oct 2013
0 downloads since 12 months
Detailed statistics

Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:07 Faculty of Science > Department of Chemistry
Dewey Decimal Classification:540 Chemistry
Language:English
Date:2002
Deposited On:03 Oct 2013 07:44
Last Modified:05 Apr 2016 17:00
Publisher:Wiley-Blackwell
ISSN:0018-019X
Funders:Polish State Committee for Scientific Research (Grant No. 3 TO9A 00716, Swiss National Science Foundation, F. Hoffmann-La Roche AG, Basel, Dr. Helmut Legerlotz-Stiftung, Universität Zürich
Publisher DOI:https://doi.org/10.1002/1522-2675(200202)85:2<451::AID-HLCA451>3.0.CO;2-9

Download