In 2016, the large variety of publications focused on the synthesis of O- and
S-6-membered ring systems highlights the importance and popularity of
these heterocyclic compounds.
Reviews on natural products covered the origins and medicinal use of
avermectins (16AGE10190), discovery, isolation, characterization and application
of artemisinin (16AGE10210), biosynthesis of fungal meroterpenoids
(16NPR26), isolation, biological properties, and synthesis of dimeric pyranonaphthoquinones
(16EJO5778), and peroxide and peroxide-derived
polyketide metabolites from marine sponges (16NPR861). Late-stage convergent
annulation reactions (16T3345) and rhodium-catalyzed annulation
reactions of arenes with alkynes via weak chelation-assisted CdH activation
(16CC2872) for the synthesis of several natural six-membered oxacycles
have also been reviewed.
New approaches for the synthesis of naturally occurring bioactive pyran
derivatives have appeared. Different routes have been established for the
total synthesis of tetrahydropyran-containing natural compounds brevisamide
(16EJO2300, 16JOC3799), (±)-centrolobine (16SL2221), (−)-clavosolide A
(16AGE2498), (+)-decarestrictine L (16TL4368), decytospolide A, B, and
their C-3 epimers (16S765), goniodomin A (16JOC2213), herboxidiene
(16OBC6212), irciniastatins (16JOC1930), (−)-lasonolide A (16JA11690),
(−)-luminacin D (16JOC3818), (−)-mandelalide A (16JA770, 16JA3675),
isomandelalide A (16JA770), thailanstatin A (16JA7532); of the 2H-pyran-
2-ones sibirinone, (E)-6-(pent-1-en-1-yl)-2H-pyran-2-one and (E)-6-
(hept-1-en-1-yl)-2H-pyran-2-one (16JOC10357); of the 5,6-dihydropyran-
2-one derivatives cryptomoscatone F1 (16S1561), cryptorigidifoliol B
(16TL2100), cryptorigidifoliol E (16S4213), 8-methoxygoniodiol (16S4300), pectinolides A, C, and H (16HCA247); and of the tetrahydropyran-2-one
derivatives (−)-(S)-goniothalamin and (−)-leiocarpin (16SC187), helicascolides
A, B, and C (16AGE5765), isodaphlongamine H (16AGE2577), and
(−)-malyngolide and its C-5 epimer (16HCA267).
