. Author manuscript; available in PMC: 2010 Mar 1.

Published in final edited form as: Org Biomol Chem. 2009 Jun 19;7(16):3331–3337. doi: 10.1039/b908205k

Table 2.

Cyclopropanations of Chiral α-Substituted Allenamides.


entry	allenamide	R =	time [h]	yield [%] [ratios]^a
1	32	Me	3	36-M: 38 [3.5:1] 36-B: 26 [3.5:1]
				overall dr = 3.5:1^b
2	32	Me	16	36-M: 19^c [10.0:1] 36-B: 36 [3.0:1]
				overall dr = 4.1:1^b
3	33	n-Bu	3	37-M: 37^d [5.0:1] 37-B: 18 [≥20:1]
				overall dr = 7.9:1^b
4	33	n-Bu	16	37-M: 30^d [6.0:1] 37-B: 22 [≥20:1]
				overall dr = 11.1:1^b
5	34	Bn	16	38-M: 32 [7.0:1] 38-B: 20 [≥20:1]
				overall dr = 12.0:1^b
6	35	CH₂C₆H₄[o-Ph]	3	39-M: 36 [5.0:1] 39-B: 23 [≥20:1]
				overall dr = 8.8:1^b

^(a)

Isolated yields. Dr ratios are in the bracket with the respective major diastereomer being shown in the scheme and all ratios were assigned using crude ¹H NMR.

^(b)

Overall dr ratios represent the combined dr for the first cyclopropanation.

^(c)

NMR yield.

^(d)

See reference ⁴².