TY - JOUR
T1 - Arylmagnesium Bromide Additions to 1-Tetralone-2-acetic Acid Followed by Catalytic Hydrogenolysis
T2 - Stereochemical Consequences
AU - Djerassi, Carl
AU - Pettit, George
AU - Herald, Delbert L.
AU - Sanson, Dale R.
PY - 1991/8/1
Y1 - 1991/8/1
N2 - A Stork reaction route (7 → 1b) was utilized to synthesize 1-tetralone-2-acetic acid methyl ester (1a) from 1-tetralone. Addition of a 2′-(o-methoxyphenyl) magnesium bromide to this ketone followed by palladium-catalyzed hydrogenation of the intermediate cis lactones (2, verified by X-ray crystal structure determination of 2a, Figure 1), afforded predominantly a 1,2-cis tetralin (3) accompanied by smaller yields of the corresponding 1,2-trans tetralin (4). The stereochemical consequences of this reaction sequence was unequivocally established by X-ray crystal structure elucidation of 1,2-cis methyl ester 3b (Figure 2) and 1,2-trans carboxylic acid 4a (Figure 3). Stereochemical assignments for the analogous diastereoisomeric sets 3c-f and 4c-f were obtained by high-field (400-MHz) 1H and 13C NMR correlations with the crystal structures. The overall reaction pathway illustrates a useful approach to 1,2-cis-alkylated tetralins and certain sterically hindered 1,2-trans-alkylated tetralins.
AB - A Stork reaction route (7 → 1b) was utilized to synthesize 1-tetralone-2-acetic acid methyl ester (1a) from 1-tetralone. Addition of a 2′-(o-methoxyphenyl) magnesium bromide to this ketone followed by palladium-catalyzed hydrogenation of the intermediate cis lactones (2, verified by X-ray crystal structure determination of 2a, Figure 1), afforded predominantly a 1,2-cis tetralin (3) accompanied by smaller yields of the corresponding 1,2-trans tetralin (4). The stereochemical consequences of this reaction sequence was unequivocally established by X-ray crystal structure elucidation of 1,2-cis methyl ester 3b (Figure 2) and 1,2-trans carboxylic acid 4a (Figure 3). Stereochemical assignments for the analogous diastereoisomeric sets 3c-f and 4c-f were obtained by high-field (400-MHz) 1H and 13C NMR correlations with the crystal structures. The overall reaction pathway illustrates a useful approach to 1,2-cis-alkylated tetralins and certain sterically hindered 1,2-trans-alkylated tetralins.
UR - http://www.scopus.com/inward/record.url?scp=21644447207&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=21644447207&partnerID=8YFLogxK
U2 - 10.1021/jo00018a030
DO - 10.1021/jo00018a030
M3 - Article
AN - SCOPUS:21644447207
VL - 56
SP - 5360
EP - 5368
JO - Journal of Organic Chemistry
JF - Journal of Organic Chemistry
SN - 0022-3263
IS - 18
ER -