AUTHOR OF THIS BLOG

DR ANTHONY MELVIN CRASTO, WORLDDRUGTRACKER
Oct 102017
 

STR1

Total synthesis of (-)-aritasone via the ultra-high pressure hetero-Diels-Alder dimerisation of (-)-pinocarvone

Org. Biomol. Chem., 2017, Advance Article

DOI: 10.1039/C7OB02204B, Paper
Maliha Uroos, Phillip Pitt, Laurence M. Harwood, William Lewis, Alexander J. Blake, Christopher J. Hayes
The total synthesis of aritasone via the proposed biosyntheic hetero-Diels-Alder [4 + 2] cyclodimerisation of pinocarvove, has been achieved under ultra-high pressure (19.9 kbar) conditions

Total synthesis of (−)-aritasone via the ultra-high pressure hetero-Diels–Alder dimerisation of (−)-pinocarvone

 Author affiliations

Christopher Hayes

Abstract

This paper describes a total synthesis of the terpene-derived natural product aritasone via the hetero-Diels–Alder [4 + 2] cyclodimerisation of pinocarvove, which represents the proposed biosyntheic route. The hetero-Diels–Alder dimerisation of pinocarvone did not proceed under standard conditions, and ultra-high pressure (19.9 kbar) was required. As it seems unlikely that these ultra-high pressures are accessible within a plant cell, we suggest that the original biosynthetic hypothesis be reconsidered, and alternatives are discussed.

STR1 STR2
Aritasone (1) A solution of pinocarvone (()-2) (100 mg, 0.66 mmol) in dichloromethane (5 mL) was pressurized to 19.9 kbar for 120 h. The 1H NMR spectrum of the crude reaction mixture showed significant change in the composition as compared to the starting material. The solvent was evaporated and the residue was purified by column chromatography (pentane/Et2O; 25/1) to afford aritasone (1) (20 mg, 40%) as a white solid; mp 101- 103 C; (lit3 mp 105-106 °C); []D 26 26.1 (c 0.40 in CHCl3); (lit3 []D 9 118); max/cm-1 (CHCl3) 2926, 2359, 1722, 1689, 1601, 1467, 1372, 1305, 1152; H (400 MHz; CDCl3, 298 K) 2.67 (2H, app dd, J 4.8, 2.5, H-2a, H-2b), 2.45-2.32 (3H, m, H-7a, H-15a, H-3), 2.15-2.01 (4H, m, H-10, H-12, H-15b, H-16a), 1.91-1.80 (2H, m, H-4, H-16b), 1.66 (1H, ddd, J 13.8, 6.4, 3.4, H-7b), 1.38 (3H, s, CH3), 1.29-1.22 (7H, br s, CH3, H-13a, H-13b, H-8a, H- 8b), 0.90 (3H, s, CH3), 0.80 (3H, s, CH3); C (100 MHz; CDCl3, 298 K) 209.5 (C), 142.9 (C), 112.8 (C), 80.8 (C), 45.2 (CH), 44.3 (CH), 43.7 (CH2), 40.9 (CH), 40.5 (C), 39.4 (CH), 38.3 (C), 33.2 (CH2), 32.7 (CH2), 27.7 (CH3), 27.3 (CH2), 27.3 (CH3), 26.3 (CH3), 22.5 (CH2), 22.1 (CH2), 20.9 (CH3); HRMS m/z (ES+ ) found 301.2162 (M + H) C20H29O2 requires 301.2162 and 323.1981 (M + Na) C20H28O2Na requires 323.1982. These data were consistent to those previously reported, 5, 7 however the value of the specific rotation5 differs significantly from that measured during the original isolation work.3

Christopher Hayes

Contact

Biography

Prof. Christopher Hayes began his academic career here in Nottingham with his B.Sc. in July 1992. Remaining at Nottingham, he completed his Ph.D. studies in organic chemistry, under the supervision of Professor Gerald Pattenden, in September 1995. In January 1996, on a NATO Postdoctoral Fellowship, he moved to the University of California at Berkeley where he worked in the group of Professor Clayton H. Heathcock. In September 1997, he returned to Nottingham as a Lecturer in Organic Chemistry, and has subsequently been promoted to Reader (2003), Associate Professor (2006) and Professor of Organic Chemistry (2011).

Research Summary

Research is centred in main-stream synthetic organic chemistry, focusing on the organic chemistry of biologically active molecules. His current research interests span a number of areas such as (i)… read more

Recent Publications

Share
Follow

Get every new post on this blog delivered to your Inbox.

Join other followers: