Table 1: Radical hydrostannation of (S)-1a and (S)-1b.

Entry Diester R3SnH Diester/R3SnH
Relation
A/ Ba 119SnNMR (δ, ppm)c Yield
(%) d
% De
(A)b Cpd. Nº (B)c Cpd. Nº
1 (S)-1a n-Bu3SnH 1: 2.4 31/69 -7.08 (S)-2 -7.39 (S)-3 67 100
n-Bu3SnH 1: 3 20/80 -7.08 (S)-2 -7.39 (S)-3 45 100
2 Ph3SnH 1: 2.4 0/100 -f - -99.05 (S)-4 86 100
3 (S)-1b n-Bu3SnH 1: 2.4 0/100 -f - -11.34
-11.40
-11.82
-11.86
5a-d 67 50
13
25
12
4 Ph3SnH 1: 2.4 0/100 -f - -103.38
-103.73
-104.02
-104.20
6a-d 84 8
19
42
31

a Proportion of mono (A) and di-addition (B) products determined by integration in the 119SnNMR spectrum; b Single
addition adduct; c Double addition adduct; c Chemical shift determined in CDCl3 respect to Me4Sn; d Yield of the isolated
di-addition products; e Diastereomeric relationship determined by integration in the 119SnNMR spectrum; f Not observed