Enantioselective Additions of Diethylzinc and Diphenylzinc to

ORGANIC LETTERS 2002 Vol. 4, No. 23 4183

Additions and Corrections

Vol. 3, 2001

Amos B. Smith, III* and Michael Frohn Lituarine Synthetic Studies. An Efficient, Stereocontrolled Construction of the Common C(7-19) Tricyclic Spiroketal Fragment. Page 3982, Figure 1. Two structures were numbered incorrectly; the correct numbers are shown below.

Vol. 4, 2002

Dong-Hyun Ko, Deok-Chan Ha*

Kyoung

Hoon

Kim,

and

Enantioselective Additions of Diethylzinc and Diphenylzinc to Aldehydes Using 2-Dialkylaminomethyl-2′-hydroxy-1,1′binaphthyls. Page 3761, Table 4. The numbering of ligands is presented incorrectly. The ligands in entries 3, 4, 6, and 7 in Table 4 should be 3d, 3e, 3f, and 3d, respectively. Ligand 3f in footnote c of Table 4 should be 3d.

Table 4. Addition of Diphenylzinc to p-Anisaldehyde Using Ligands 3a-f

Page 3980, reference 9. The predicted equilibrium ratio of the C(16) epimers of 4 should read 5.3:1. These calculations do not support the speculation that the experimentally derived ratio of 1.4:1 is at equilibrium (page 3982). OL0201308

10.1021/ol0201308 Published on Web 10/22/2002

entry 1 2 3 4 5c 6 7d

ligand 3a 3b 3d 3e 3d 3f 3d

t (h)

isolated yield (%)

ee (%)a,b

1 1 1 1 10 1 24

71 93 97 95 94 97 75

88 87 95 94 90 98 98

a Determined by HPLC (Chiralcel OJ column). b Absolute configuration assigned by comparison to the literature. c Using 5 mol % catalyst 3d. d A mixture of Ph2Zn (1 equiv) and Et2Zn (2 equiv) was used.

OL027091K 10.1021/ol027091k Published on Web 10/25/2002