Skip to main content
. Author manuscript; available in PMC: 2008 Aug 21.
Published in final edited form as: Org Lett. 2007 May 4;9(11):2143–2146. doi: 10.1021/ol070616u

Table 1.

Synthesis of simplified, C4-unsubstituted salinosporamide/cinnabaramide derivatives 19a–d

graphic file with name nihms62335f6.jpg
Entry R1 % yield (17)a,b % yield (19)b dr c
1 CyCH2 84 (17a) 93 (19a) 2.2:1
2 nHexyl 80 (17b) 90 (19b) 2.2:1
3 PhCH2 72 (17c) 85 (19c) 2.5:1 (>19:1)d
4 H 77 (17d) 25 (19d) -
a

Yield is for 2 steps.

b

Yields refer to isolated, purified (SiO2) product.

c

Determined by 1H NMR analysis of crude reaction mixtures.

d

Observed diastereomeric ratio (dr) if reaction is allowed to proceed at 25 °C for 1.5 d (54% yield). PMB = p-methoxybenzyl, 4-PPY = 4-pyrrolidinopyridine, Cy = cyclohexyl.