TY - JOUR
T1 - Diastereomerically pure 1,2-diols by nucleophilic displacement reactions of 3-oxetanols - A study directed towards the identification of suitable nucleophiles and the elucidation of possible side reactions
AU - Bach, Thorsten
AU - Eilers, Frank
PY - 1998/10
Y1 - 1998/10
N2 - The ring opening of 3-isopropyl-2-phenyl-3-oxetanol (2a) by various nucleophiles has been studied. In the presence of BF3 as a Lewis acid, a clean reaction at the less substituted C-4 position was observed and the corresponding 1,2-diols 6-11 and 21-23 were isolated in diastereomerically pure form (47-97% yield). Alkyl-, aryl-, alkynyl- and alkenyllithium compounds proved to be suitable carbon nucleophiles. Deprotonated thiols were used as sulfur nucleophiles. An alkoxide derived from benzyl alcohol and an amide derived from benzylamine reacted less readily under these conditions, yielding the 1,2,3-trifunctional compounds 24 (42% yield) and 26 (54% yield). Other 2-phenyl-3-oxetanols such as 2b and 2c can also be employed as electrophiles, whereas 2-anisyl derivatives preferentially undergo rearrangement reactions, as exemplified by the conversion of oxetane 16 to the hydroxy ketone 17 (84% yield). The superior behaviour of 3-oxetanols as compared to their silyl derivatives in reactions with nucleophiles became evident from the reaction of 3-silyloxyoxetane 1a with alkyllithium reagents. A β elimination occurred upon treatment with nBuLi, which, after pericyclic ring opening and addition of nBuLi, yielded the allylic alcohol 20.
AB - The ring opening of 3-isopropyl-2-phenyl-3-oxetanol (2a) by various nucleophiles has been studied. In the presence of BF3 as a Lewis acid, a clean reaction at the less substituted C-4 position was observed and the corresponding 1,2-diols 6-11 and 21-23 were isolated in diastereomerically pure form (47-97% yield). Alkyl-, aryl-, alkynyl- and alkenyllithium compounds proved to be suitable carbon nucleophiles. Deprotonated thiols were used as sulfur nucleophiles. An alkoxide derived from benzyl alcohol and an amide derived from benzylamine reacted less readily under these conditions, yielding the 1,2,3-trifunctional compounds 24 (42% yield) and 26 (54% yield). Other 2-phenyl-3-oxetanols such as 2b and 2c can also be employed as electrophiles, whereas 2-anisyl derivatives preferentially undergo rearrangement reactions, as exemplified by the conversion of oxetane 16 to the hydroxy ketone 17 (84% yield). The superior behaviour of 3-oxetanols as compared to their silyl derivatives in reactions with nucleophiles became evident from the reaction of 3-silyloxyoxetane 1a with alkyllithium reagents. A β elimination occurred upon treatment with nBuLi, which, after pericyclic ring opening and addition of nBuLi, yielded the allylic alcohol 20.
KW - 1,2-Diols
KW - Alkyldealkoxylation
KW - Oxetanes
KW - Photocycloaddition
KW - Ring opening
UR - http://www.scopus.com/inward/record.url?scp=0004680937&partnerID=8YFLogxK
U2 - 10.1002/(SICI)1099-0690(199810)1998:10<2161::AID-EJOC2161>3.0.CO;2-L
DO - 10.1002/(SICI)1099-0690(199810)1998:10<2161::AID-EJOC2161>3.0.CO;2-L
M3 - Article
AN - SCOPUS:0004680937
SN - 1434-193X
SP - 2161
EP - 2169
JO - European Journal of Organic Chemistry
JF - European Journal of Organic Chemistry
IS - 10
ER -