tailieunhanh - Asymmetric synthesis of a new silafuran

The absolute configuration was assigned by analogy. HPLC with chiral column was use to prove the ratio of enantiomer excess. All new compounds were characterized with IR, NMR and MS spectra. | JOURNAL OF SCIENCE OF HNUE Chemical and Biological Sci. 2014 Vol. 59 No. 9 pp. 43-50 This paper is available online at http ASYMMETRIC SYNTHESIS OF A NEW SILAFURAN Duong Quoc Hoan Faculty of Chemistry Hanoi National University of Education Abstract. Silanediols are being considered recently due to their good biological activities such as HIV inhibition and inhibition of angiotensin-converting enzymes ACE . Synthesis of silanediols needs to have various analogs of silafurans. An asymmetric synthesis of silafuran S -4- 2- 1 3-dioxolan-2-yl ethyl -2 2-diphenyl-2-silafuran containing a functional group was produced successfully in this work using the chiral catalyst ferrotan. The absolute configuration was assigned by analogy. HPLC with chiral column was use to prove the ratio of enantiomer excess. All new compounds were characterized with IR NMR and MS spectra. Keywords Silanediol silafuran silyl ether ferrotan enantiomer excess. 1. Introduction Organisilanes are not naturally made. However with modification of well known biologically active compounds to silicon analogs there is a high chance of success. For example the design of C2 symmetry-based inhibitors that mimic the symmetry of the human immunodeficiency virus type-1 HIV-1 was described by Erickson et al. 3 and Kempf et al. 7 . Based on that strategy Merck designed a new set of pseudo C2 symmetric inhibitors based upon L-685 434 IC50 nM named L-700 417 1 IC50 nM . Silanediol 2 was found to have a Ki of nM for inhibition of HIV-1 only slightly less effective than carbon analog 1 Figure 1 2 . Silanediol protease inhibitor 4 was assembled as an analog of Almquist s ketone-based Angiotensin-converting enzyme ACE inhibitor 3. Ketone 3 was found to have an IC50 of 1 nM whereas silanediol 4 was found to have an IC50 value of nM 8 . Silanediol 6 a metalloprotease inhibitor of thermolysin was prepared by analogy to the phosphinic acid inhibitor 5. Inhibition of thermolysin by .